Naruto- Secret Sage

Chakra is comprised of two primary components and five subsidiary ones. Yin and yang energy are the primary components. Yin energy is the power of the mind or soul and dictates the nature and purpose of chakra. Yang energy is the energy of the body as is the power and shape of chakra. From there chakra can be further split into a vast array of elements and powers however the very basics are the five subsidiary chakra natures. Fire, water, earth, wind and lightning are the basic natures that build each of the more complex ones.

An example is fire + water = steam chakra. 

For the vast majority of ninjas one or two of these basic natures are what they have dominantly in their chakras. While it remains true that a ninja is not limited to using only their dominant chakra natures few ever put in the considerable amount of work required to learn all of them beyond a small degree. Creating a combined chakra element such as steam requires one of two things however. The first is a Kekkai Genkai or bloodline limit. These are an innate understanding of and ability to use a combined chakra element due to ones ancestor having mastered the fusion of two basic elemental energies.-

The second method is of course self creation of the combined elements through sheer mastery of the basic chakra natures and going even a step further to fuse them together. This is by far the highest form of mastery achievable with ones chakra elements and as a result very few ever succeed. Finally there is the last type of energy that can be added to chakra , natural energy. Natural energy unlike chakra is ever present and comes from outside of ones self with only a few exceptions. Natural energy is the energy of the world itself in many ways and takes the traits of those that live within and "taint" a certain area for a certain amount of time.-

When natural energy is taken into a ninjas body and mixed with their chakra a new form of power is born, Sage chakra. It should be noted however that this process of taking in natural energy is dangerous for most as nature energy will seek to flood into the body and bring it in tune with nature. If not controlled correctly this will cause one to permanently take the features of whatever being has tainted the natural energy in that area at best or at worse turn one into a stone statue.-

If one is successful in creating Sage chakra however one will enter a heightened state known as "Sage mode" that grants a vast increase in physical strength , speed , reaction time , energy based attacks and the aptly named Senjutsu or Sage arts. These Sage arts add natural energy to a technique or use it as fuel for one which in turn massively and in most cases qualitatively transforms the attack into a powerful force of destruction or in extremely rare cases creation.-

Ninjutsu and Senjutsu are created by ninjas who learned how to control their chakra and transform it into elemental or neutral energy based forms with a vast degree of versatility. They achieve this through two main methods. The first is handsigns that when used cause ones chakra to internally shift and mold into the shape and nature of the attack or technique being wanted. The more complex the handsigns needed the more powerful or complex a technique is. The second method is internal molding in which the ninja is so familiar with the chakra transformation into the technique using handsigns that they no longer need hand signs to pull it off. -

This is only ever seen at higher levels of shinobi however as it requires a vast amount of practice and muscle memory. Moving on we have a daily facet of ninja life that many take for granted or underestimate, Seals or fuinjutsu. Fuinjutsu is the use of written symbols to achieve an effect when chakra is added to them or a condition is fulfilled. The exact nature of fuinjutsu is static for the most part as seals will only ever do what the symbols allow them to in a manner very reminiscent of computer coding.-

The main differences however are that seals have very physical effects on reality and can be applied to more than just a single type of thing. For example a fire creation seal could be used by a blacksmith just as well as in battle against an enemy ninja. In theory fuinjutsu's limit is only the skill and knowledge of the one using it but few examples of this are known beyond the sealing of the ten tailed beast.-

Next up is the tailed beasts, sage beasts and chakra beasts beneath them in the natural order. Tailed beast is a title granted to nine creatures quite literally made of chakra and natural energy originally but has since extended to any other creature that fulfills those conditions as well. The original tailed beasts however have long since been sealed within living hosts who are known as jinchuriki. These jinchuriki are considered secret weapons by the villages who possess them and few are aware that these same nine tailed beasts can be fused together again to recreate the ten tailed beast that had been sealed away long ago.-

Chakra beasts on the other hand are far more common and is a title held by any animal that gains the ability to use chakra in any regard. These same animals are typically much more powerful than their normal counterparts and tend to have special abilities as well. Ninjas are well known to sign summoning contracts with these beasts to have them aid them. Finally there are the sage beasts. They are much like chakra beasts in that they can use chakra but unlike the chakra beasts , Sage beasts have evolved to gain sapience and the ability to utilize natural energy as well.-

Many think that there are only three kinds of sage beasts but that is incorrect as there are in fact only three who are known to take an active participation in the affairs of the world beyond their "sage region". These three are the "three unexplored mystic regions" Mount Myoboku home to the toad sage beasts, Ryuchi cave home to the snake sage beasts and Shikkotsu forest home to the slug sage beast Katsuyu who can divide herself into many smaller slugs to be used but is in fact only a single sage beast. The other sage beasts simply don't bother themselves with the affairs of the world and are thus unknown for the most part.